A variety of therapeutic approaches have been attempted in the treatment of post-ischemic tissue injury. Some approaches advocate the scavenging of superoxide free radicals while others suggest the inhibition of enzymes present in the various metabolic pathways, such a the enzyme xanthine oxidase. See, e.g., Simpson, et al., Federation Proceedings, 46 (7), 2413 (1987). Another approach involves the inhibition of superoxide production and release by activated polymorphonuclear leukocytes--see, e.g., Columns 1 and 2 of U.S. Pat. No. 4,668,676. Compounds of this latter class are specially well suited for preventing the formation of toxic oxygen radicals and therefore should be effective agents for minimizing tissue damage resulting from an inflammatory or ischemic event.